Question

How many 176 Ω resistors (in parallel) are required to carry 5 A on a 220 V line?

Answer 1

For x number of resistors of resistance 176 Ω, the equivalent resistance of the resistors connected in parallel is given by Ohm's law as \(V= IR\)
\(R= \frac VI\)
Where,
Supply voltage, \(V= 220 \ V\)
Current, \(I = 5\  A\)
Equivalent resistance of the combination = \(R\), given as
\(\frac 1R = x \times (\frac {1}{176})\)

\(R = \frac {176}{x}\)
From Ohm's law,
\(\frac VI = \frac {176}{x}\)
\(x = 176 \times \frac IV \)

\(x= 176 \times \frac {5}{220}\)
\(x= 4\)

Therefore, four resistors of 176 Ω are required to draw the given amount of current.